1. Field of the Invention
The present invention relates an apparatus, system, and method for replacing a welding tip used for gas shielded arc welding.
2. Description of the Related Art
In gas shielded arc welding, a disposable copper electrode called a contact tip (hereinafter, referred to as a “welding tip”) is typically used as a member for supplying current to a wire. The welding tip has a through-hole. The wire is continuously fed to the through-hole and current is supplied to the wire through the welding tip, thus generating an electric arc between the wire protruding from the distal end of the welding tip and a base material.
During gas shielded arc welding, the wire rubs against the inner surface of the through-hole at the distal end of the welding tip, so that relevant portions become worn. Accordingly, the inside diameter of the through-hole is increased, thus shifting a welding position or causing poor current supply to the wire. It is therefore necessary to periodically replace the welding tip.
In automatic long-time welding, such a welding tip replacing operation contributes to the availability of a welding facility.
Manual replacement of welding tips requires time and effort, which may significantly reduce the availability of the welding facility. Research, development, and practical application of welding tip replacement apparatuses capable of automatically replacing a welding tip are therefore in progress.
For example, Japanese Unexamined Patent Application Publication Nos. 6-312266 and 11-347731 disclose a small replacement apparatus capable of easily replacing a welding tip. Furthermore, Japanese Unexamined Patent Application Publication No. 2010-149145 discloses a replacement apparatus capable of dealing with different sized welding torches and different sized welding tips.
Each of techniques disclosed in the above-described three patent application publications relates to the welding tip replacement apparatus designed for a welding torch including a welding tip and a body (hereinafter, referred to as a “tip connection body”) which are detachably engaged with each other in a screw threaded manner. Such a welding tip replacement apparatus, therefore, requires a rotator for rotating the welding tip. In addition, a mechanism for applying a large torque to the rotator is needed to securely attach the welding tip to the welding torch such that the welding tip is prevented from being easily detached from the welding torch and is also needed to detach the securely attached welding tip. Accordingly, such a welding tip replacement apparatus has to have a complicated structure.